:bug: removed hardcoded modulo in batching

backend/db/seeds/01-users.js

 const mock = require('../data-generator/mock')
 const fs = require('fs')
 const dataSort = require ('../dataSort')
+const { batchSize } = require('../data-generator/config.json')
 
 let users = []
 const generatedDataPath = './db/generated'
     let len = users.length
     for (let i = 1; i <= len; i += 1) {
         usersToPush.push(users.shift())
-        if (i % 500 === 0) {
+        if (i % batchSize === 0) {
             await knex('users').insert(usersToPush)
             usersToPush = []
         }

backend/db/seeds/02-profiles.js

 const mock = require('../data-generator/mock')
 const fs = require('fs')
 const dataSort = require ('../dataSort')
+const { batchSize } = require('../data-generator/config.json')
 
 
 let profiles = []
     let len = profiles.length
     for (let i = 1; i <= len; i += 1) {
         profilesToPush.push(profiles.shift())
-        if (i % 500 === 0 || i > profiles.length) {
+        if (i % batchSize === 0 || i > profiles.length) {
             await knex('profiles').insert(profilesToPush)
             profilesToPush = []
         }

backend/db/seeds/04-responses.js

 const mock = require('../data-generator/mock')
 const fs = require('fs')
 const dataSort = require ('../dataSort')
+const { batchSize } = require('../data-generator/config.json')
 
 let responses = []
 const generatedDataPath = './db/generated'
     let len = responses.length
     for (let i = 1; i <= len; i += 1) {
         responsesToPush.push(responses.shift())
-        if (i % 500 === 0 || i > responses.length) {
+        if (i % batchSize === 0 || i > responses.length) {
             await knex('responses').insert(responsesToPush)
             responsesToPush = []
         }